1. Field of the Invention
The present invention relates to a board to board connector, particularly to a board to board connector in which the spring portion has a two-way multi-layer U-shaped structure with perfect resilience and low shrink range, to meet the requirements of high insertion durability.
2. Description of Related Art
Board to board connector mounted, between printed circuit boards (PCBs) is used to provide signal transmission among electronic devices. At present, the board to board connector has two configurations. One is the connector consists of a plug and a receptacle connector, the other is only a simplex connector used alone, i.e. it is a single connector in which the solder portion and contact portion thereof are each connected with a PCB to achieve signal transmission, the structure of this kind of board to board connector is relatively simple.
For example, U.S. Pat. Nos. 6,276,941 and 6,142,790, both disclosed the board to board connectors are of a single connector configuration, and apparent defaults could be found in the two patents. Firstly, the elastic contact portion (abutted against the PCB) and the mounting portion (mounted in the insulative housing) of the terminal define a relatively large angle, and the elastic contact portion surpasses the insulative housing largely, when the contact portion is contacted with the PCB, they need to apply a strong force to press them to the same level with the upper surface of the insulative housing, which is adverse for operation, and the resilience restoring ability of the terminal is relatively poor. Secondly, as time passes, the elastic contact portion would become poor on restoring resilience and surpass further out of the insulative housing, which is adverse for using. On account of the above adverse factors, the existing board to board connectors are to be improved.